//接收命令行参数
var arg = process.argv[2];//前两个元素固定
if((typeof arg) == undefined){
    console.log("sorry");
}

if(arg == '--help'){
    console.log("program --help");
}

var result = eval(arg);
if(!isNaN(parseInt(result))){
    console.log(arg + "=" + result);
}

